If you make production parts for an automotive or aerospace customer, two acronyms shape how you launch a product: APQP and PPAP. They sound like bureaucracy, but the idea underneath them is simple and good: plan quality in before you build, then prove the process works before you ship. This guide explains the method end to end — what each piece is for, how the pieces connect, and where teams usually go wrong.
What APQP is
APQP — Advanced Product Quality Planning — is a structured framework for developing a new part so that it reliably meets the customer's requirements in real production. Instead of designing a part, throwing it over the wall to manufacturing and inspecting quality in at the end, APQP front-loads the thinking: you identify risks, define controls and validate capability before the part reaches volume. It is organised into five phases, and each phase produces the inputs the next one needs.
The five phases of APQP
- Plan and define the program. Turn the voice of the customer, the targets and the known special characteristics into a quality plan and a program timeline.
- Product design and development. The design itself, the Design FMEA (DFMEA), design verification and the drawings — the outputs your process will have to deliver.
- Process design and development. How the part will actually be made: the process flow, the Process FMEA (PFMEA) and the control plan. This is where most of a supplier's APQP work lives.
- Product and process validation. Trial production runs, Measurement System Analysis (MSA), initial process studies (Cpk/Ppk) and the PPAP submission that proves the process is capable.
- Launch, feedback and corrective action. Ramp to full volume, monitor with the control plan, and feed any escapes back into the PFMEA so the analysis stays true.
What PPAP is
PPAP — the Production Part Approval Process — is the deliverable that lives mostly in phase four. It is a standardized package of evidence a supplier submits so the customer can approve the part for production. The crucial point: PPAP is not a separate pile of paperwork you generate at the end. Its engineering elements — the process flow, the PFMEA and the control plan — are the very artifacts you built in phase three. A good PPAP is a snapshot of work you've already done well, not a fire drill.
PPAP defines 18 elements and five submission levels. The level (set by the customer) decides how much of the package you actually send; Level 3 — the Part Submission Warrant plus samples and complete supporting data — is the common default for automotive parts.
The heart of it: the PFMEA
The Process Failure Mode and Effects Analysis is where the method earns its keep. For each step of your process you ask three questions: how could this step fail (the failure mode), what happens if it does (the effect), and why might it happen (the cause). You then rate three things on a 1–10 scale:
- Severity (S) — how bad the effect is, with 9–10 reserved for safety or regulatory consequences.
- Occurrence (O) — how often the cause is expected to happen.
- Detection (D) — how likely your current controls are to catch the problem before it escapes (10 = undetectable).
From those three scores, the AIAG-VDA method assigns an Action Priority of High, Medium or Low. Action Priority replaced the old Risk Priority Number in 2019 — a change worth understanding, because it changes how you triage. We cover it in depth in Action Priority vs RPN, and the mechanics of a workshop in How to run a PFMEA, step by step.
Control plans and special characteristics
A PFMEA finds the risks; the control plan is the promise of how you'll manage them in production. Each control-plan line ties a process step and a characteristic to a specification, an evaluation method, a sample size and frequency, a control method and a reaction plan — what you do when something goes out of bounds.
The thread that runs through everything is the special characteristic: a feature, critical or significant, that needs extra control because it affects safety, fit, function or compliance. A special characteristic identified in design has to appear in the PFMEA and be controlled in the control plan. When it doesn't propagate everywhere it should, that's the classic audit finding. (More in Special characteristics explained.)
The 18 PPAP elements and the PSW
The full element list is: Design Records; Engineering Change Documents; Customer Engineering Approval; Design FMEA; Process Flow Diagram; Process FMEA; Control Plan; Measurement System Analysis; Dimensional Results; Material & Performance Test Results; Initial Process Studies; Qualified Laboratory Documentation; Appearance Approval Report; Sample Production Parts; Master Sample; Checking Aids; Customer-Specific Requirements; and the Part Submission Warrant (PSW) — element 18, the cover sheet you sign to certify the submission. The PSW is only meaningful when every applicable element behind it is genuinely complete.
Why Action Priority replaced the RPN
The old approach multiplied Severity × Occurrence × Detection into a Risk Priority Number from 1 to 1000, then chased the biggest numbers. The flaw: a trivial-but-frequent nuisance (S2 × O9 × D9 = 162) outranked a dangerous-but-rare failure (S10 × O2 × D3 = 60). Teams ended up "managing the arithmetic." The AIAG-VDA Action Priority table fixes this by weighting Severity first: a safety-relevant failure is High regardless of how rarely it occurs. It's a more honest way to decide where to spend engineering effort.
The hard part: keeping it alive
Here's the uncomfortable truth of APQP: most of these documents are correct on the day they're signed and slowly rot afterwards. The process flow gets a new step that never reaches the PFMEA. A special characteristic is added in design but never makes it to the control plan. The PPAP in the customer portal reflects last year's reality. The method isn't wrong — the maintenance model is.
That's the problem SolidLaunchpad is built for. It keeps the process flow, PFMEA, control plan and PPAP as one connected model: the same steps and special characteristics flow through everything, the hard AIAG/VDA rules check themselves, and the PPAP's engineering elements are live links rather than re-uploaded copies. And because the blank page is the hardest part, AI drafts a method-correct first PFMEA and control plan from a paragraph, so your team spends its time on judgement instead of formatting.
Build a living APQP, free
From a paragraph to a submittable PPAP — with the method checking itself.
Frequently asked questions
Is APQP the same as PPAP?
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No. APQP is the planning framework — the five-phase process you follow to develop a part. PPAP is the deliverable near the end of it: the standardized package of evidence you submit to prove the process can make conforming parts at volume. You do APQP; you submit a PPAP.
Who requires APQP and PPAP?
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Automotive customers require them through IATF 16949 and their own customer-specific requirements; the methods are defined by the AIAG (and AIAG-VDA for FMEA). Aerospace uses the equivalent AS9145. In practice, any OEM or Tier-1 buying production parts will ask a supplier for a PPAP.
What is the difference between RPN and Action Priority?
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RPN multiplied Severity × Occurrence × Detection into a single number, which treated very different risks as equal. The 2019 AIAG-VDA handbook replaced it with Action Priority — a High/Medium/Low decision table that weighs Severity first, then Occurrence, then Detection, so safety-relevant failures can't be hidden by arithmetic.
How many PPAP elements are there?
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Eighteen. They run from Design Records and the Process Flow Diagram through the PFMEA, Control Plan, MSA, dimensional and material results, initial process studies and more, ending with the Part Submission Warrant (PSW) — the cover sheet the supplier signs.
What are the PPAP submission levels?
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Five. Level 1 is the PSW only; Level 2 adds samples and limited data; Level 3 (the common default) is the PSW with samples and full supporting data; Level 4 is customer-defined; and Level 5 is full records reviewed at the supplier's site.